Walt - thanks for the ideas.? C52, C55, L10 C61 and L12 all checked out good and within tolerance.? The spectrum on 15 looked as bad as on other bands.? Next I checked the 6.250 trap again and found that while I had adjusted it for a minimum, the slug was at the upper limit of travel away from the coil.? I checked C59 and found it a bit high at 35 uF, so replaced it with a 32 pF mica and now I get a true null much lower than before.? Even with all the noise present, I was able to get much better sideband suppression than before.? So really need to find the noise problem.? I pulled V5 and checked the purity of the CW and AM signals - as good as it can be with no noise or ripple at all.? I think V1 and V2 are good - scoped a sine wave all the way to the plates of V5 and it was still a nice sine wave there.? I'm going to clean the switch contacts again.? When I look at the output of T2 while feeding a 1,000 Hz tone into the mic jack in SSB mode, the output wave there looks good.? But, the? signal has an unstable look at the grid of the first mixer.? Of course it's going through a couple of switch wafers and runs of coax to and from the RF level control on CW and AM.??

Floyd

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Thank you walt. I will tackle this after work today.

Radio number 2 really runs great!? ?The RX and TX audio is much better sounding on this rig.? I am using a classic EV664. I ran it on SSB low on 80 meters for several hours.? Drift is minimal.? The Dial is the only problem I can find at this point.?

A fellow ham is sending me a NEW Load capacitor for Radio number 1, It is exactly the same cap!? ?He also had a new 8122 tube!!? He is mailing that to me as well.??

Radio number 1 will get a new load cap and then I need to find out why audio is thin.? It passes NO audio below 400hz.? I already tried the shift L15 and 16 over and that did help slightly.? I fear the Xtal filter has shifted?? ?The LSB Xtal aligns to .520 so that should be close enough?? I might try to series a 5pf cap to see if I can kick it up slightly.?

Radio number 1 also drifts UP in frequency.? Slightly up and never stops.? I have to very slightly adjust vfo back down over the course of a few minutes. This goes on for hours.?

Walt can you suggest what to do? Just change all the mica caps in VFO? Or try to change just a few??

Clark

I baked the Xtals at 360F for 2.5 hours.? They did not move in frequencey. The LSB xtal is 1648.2 and not usable.? USB is closer but still way off.? Worth a try though!
C

It is an alignment problem. See section 2-2-5 of the repair manual.?2.2.5 VFO ALIGNMENT NOTE: See section 2-2-5 of the repair manual,?

Walt, wd0gof

Is it possible the dial could have slipped on a shaft? Constant
error could be mechanical.

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

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Update.

Radio number 1 has a fault with the ball bearings missing on load cap shaft. This allows contact.? Ordered ball bearings.??

Radio number 2 is alive!? ?Its band switch was hot switched. I repaired it.? FULL power on 80 now!? ?
The CAL would not work. I found a 6u8a installed in in the V11 spot!? ?I checked the wiring. its factory. I installed a 7059 from the other rig and BINGO calibrator works.

The output was low, I found the Slug up front was out of adjustment. I checked this as walts document said it could cause this. Sure enough, one tweak and it has full drive and power.

The DIAL is off 20 KC.? ?I need to deal with that.? Not sure what to do...? Adjust the Dial or attempt to align it over. That seems far off.? It tracks fine and maintains the same 20KC offset across the band.

Making progress!!!

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I'm retiring this August, then I'll have the time to really get in deep with some of my projects, the 42 being the first.

Sent from my Verizon 4G LTE Tablet

I wonder what HT-44 owners are seeing for unwanted sideband suppression?? I'm able to get very good suppression on one sideband or the other, but finding a reasonable compromise has been elusive.

73, Floyd - K8AC

I ordered the balls off Amazon.? Good idea.? Not sure how to get them in there but they must have come out!

I also found a replacement cap on Ebay. Looks very similar.? Will get that on its way also.

Thanks!!

If they are ball bearings you may be able to get new ones from a
hardware store. If you have any of the originals you can use them to
determine the size needed.

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

I wanted to comment only on the change in capacitance value. The BB
caps I dissected all had badly distorted windings. That would change the
capacitance. Now, my first thought was that it was some way of adjusting
the value of the cap and was done deliberately but I rejected that idea
because it would affect other properties too. I do not have a
satisfactory explanation but think its likely that it was the result of
shrinkage of the casing as it was molded. I have not seen the same thing
in other capacitors. I think it would take considerable force to twist
them up in the way I observed but the cracking of the casing could have
applied it. Perhaps it had something to do with the oil filling process.
Whatever is the case its a very interesting phenomenon.
I also wonder why this did not show up in QC testing. Perhaps it
took some time, perhaps months or years for it to happen. Since it is
likely new caps would not be put into service, that is be subject to
testing, for some period of time after being manufactured, perhaps it
took considerable time for it to happen.
I wonder if anyone else has cracked apart a BB or other paper cap to
see what is in it? I also dissected some MicaMold and Solar flat paper
caps and found all looked mechanically sound despite having high
leakage. But I have not dissected many other molded resin or wax-filled
caps.
Since this is a problem of the long distant past perhaps its not
worth much discussion but my curiosity is certainly piqued.

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

I will dig into this more later in the week.
Will also check the values on the resistors in the area as well.
There is one bumblebee on the 6k6 that needs to go as well.
Was hoping to get those after I had audio, but may have to go ahead and do them.
Least I know it has power.?
Will give the 6SC6 as you suggested a look.?

73

Keith

Wow, I hadn't thought of that!? I could send it to Mouser's technical support team.? I doubt they have anyone on staff who has seen a tube oscillator circuit, but it might generate a fun story during their lunch break!?
At this point, I'm inclined to buy a crystal meant for series resonance, as there is no capacitor in parallel with the crystal.? It seems that the crystal is in one part of the feedback loop between the cathodes.? The inductor or inductor/capacitor is between plate of one and grid of the other.?
I found a SMT 16.50 MHz crystal capable of 10-100 uW power dissipation at Digikey and am tempted to use it for the WWV socket so I'd have access to the 30m band.? The voltage at the crystal is between 2.0 and 2.5 Vpp which isn't much more than it would see if wired between input and output of a TTL NOT gate.? If I were to wire a resistor in series with the crystal to measure the current, would the product of RMS current it senses and RMS voltage give a reasonable upper bound on the crystal's power dissipation?? Or would the power factor be so low that knowing such an upper bound would not be useful?
Yes, wiring the crystal under the chassis is more reliable.? For aesthetics, one could just plug in an empty HC-6 holder on top.? For some reason, I didn't do that yesterday and instead wired my MP-360s from Mouser into an HC-6 case.? To my surprise, I was able to open and reseal each HC-6 by holding it in a vise and blowing at it with the heat gun I use for heat shrink tubing.
Cheers,
Halden VE7UTS

Hello to All, once again,

First off, I want to thank you for bearing with me and for the various posts I've made.?

My recent posts have dealt with a HT-32B that had been destined as a parts rig, and may still be; however, I'm trying to see if I can make it operational once again.? In my first couple of posts, I'd thought I may have a bad transformer and/or VOX relay; fortunately, both seem to still be okay.? However, the VOX relay does not cycle when the rig is turned on and when it's switched to MOX.? In trying to understand why the relay isn't cycling, I've been checking some voltages.? Please see the following table:

Also, in MOX, the voltage coming from the LV rectifier to the relay measures 290V.? However, as can be seen in the table, the voltage at the other terminal of the relay, coming from V17, pin 1 measures about 230V, when it should be down around 160 - 170V.? It looks like the 290V - 230V differential, being only about 60V, is not enough to actuate the 120VDC relay.?? The table shows several other voltages, particularly with V16, that are WAY off from what they're supposed to be.

I'm looking for ideas and comments which might point me in a direction to take, short of simply tossing the unit aside as a parts rig..

[I should also mention that I've checked the tubes with my Sencore tester; it says they're good.? With the V16 tube, I've also swapped in a separate, known good 6AL5.? Same results]

Thanks for your time!!!!

Jim
KD0WF